DataSignaturer类：
package com.hzj.security;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.Signature;
import java.security.SignatureException;
public class DataSignaturer {
private PrivateKey privateKey;
private PublicKey publicKey;
public DataSignaturer(PublicKey publicKey, PrivateKey privateKey){
this.privateKey = privateKey;
this.publicKey = publicKey;
}
/**
* 进行数字签名
* @param data
* @return
*/
public byte[] sign(byte[] data) {
if (this.privateKey == null) {
System.out.println("privateKey is null");
return null;
}
Signature signer = null;
try {
signer = Signature.getInstance(this.privateKey.getAlgorithm());
} catch (NoSuchAlgorithmException e) {
System.out.println(e.getMessage());
}
try {
signer.initSign(this.privateKey);
} catch (InvalidKeyException e) {
System.out.println(e.getMessage());
}
try {
signer.update(data);
return signer.sign();
} catch (SignatureException e) {
System.out.println(e.getMessage());
return null;
} catch (NullPointerException e) {
System.out.println(e.getMessage());
return null;
}
}
/**
* 验证数字签名
* @param data
* @param signature
* @return
*/
public boolean verifySign(byte[] data, byte[] signature) {
if (this.publicKey == null) {
System.out.println("publicKey is null");
return false;
}
Signature signer = null;
try {
signer = Signature.getInstance(this.publicKey.getAlgorithm());
} catch (NoSuchAlgorithmException e) {
System.out.println(e.getMessage());
return false;
}
try {
signer.initVerify(this.publicKey);
} catch (InvalidKeyException e) {
System.out.println(e.getMessage());
return false;
}
try {
signer.update(data);
return signer.verify(signature);
} catch (SignatureException e) {
System.out.println(e.getMessage());
return false;
}
}
}
KeyPair类：
package com.hzj.security;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.OutputStream;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.NoSuchAlgorithmException;
public class KeyPairUtil {
// 采用的双钥加密算法，既可以用DSA，也可以用RSA
public static final String KEY_ALGORITHM = "DSA";
/**
* 从输入流中获取KeyPair对象
* @param keyPairStream
* @return
*/
public static KeyPair loadKeyPair(InputStream keyPairStream) {
if (keyPairStream == null) {
System.out.println("指定的输入流=null!因此无法读取KeyPair!");
return null;
}
try {
ObjectInputStream ois = new ObjectInputStream(keyPairStream);
KeyPair keyPair = (KeyPair) ois.readObject();
ois.close();
return keyPair;
} catch (Exception e) {
System.out.println(e.getMessage());
}
return null;
}
/**
* 将整个KeyPair以对象形式存储在OutputStream流中， 当然也可以将PublicKey和PrivateKey作为两个对象分别存到两个OutputStream流中，
* 从而私钥公钥分开，看需求而定。
* @param keyPair 公钥私钥对对象
* @param out 输出流
* @return
*/
public static boolean storeKeyPair(KeyPair keyPair, OutputStream out) {
if ((keyPair == null) || (out == null)) {
System.out.println("keyPair=" + keyPair + ", out=" + out);
return false;
}
try {
ObjectOutputStream oos = new ObjectOutputStream(out);
oos.writeObject(keyPair);
oos.close();
return true;
} catch (FileNotFoundException e) {
System.out.println(e.getMessage());
} catch (IOException e) {
System.out.println(e.getMessage());
}
return false;
}
/**
* 生成KeyPair公钥私钥对
*
* @return
*/
public static KeyPair initKeyPair() throws NoSuchAlgorithmException{
KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance(KEY_ALGORITHM);
keyPairGen.initialize(1024);
return keyPairGen.genKeyPair();
}
/**
* 生成密钥，并存储
* @param out
* @return
* @throws NoSuchAlgorithmException
*/
public static boolean initAndStoreKeyPair(OutputStream out) throws NoSuchAlgorithmException {
return storeKeyPair(initKeyPair(), out);
}
}
